Fig. 2
From: Near-infrared quantum dots labelled with a tumor selective tetrabranched peptide for in vivo imaging
Characterization of NT4-QDs. a TEM image of monodispersed NT4-QDs and unlabelled QDs. Scale bar 50 nm. b Dynamic light scattering of NT4-QDs (black line) and QDs (dotted grey line) in PBS buffer after 24 h at 25 °C. The hydrodynamic diameter (Dh) ± SD and polydispersity index (PdI) are reported in the figure. c Fluorescence spectrum of the same concentration (240 nM) of NT4-QDs and unlabelled QDs. d Cytotoxicity of NT4-QDs and free QDs in HT29 human colon adenocarcinoma cell line after 24 h incubation at 37 °C